DE3011323A1 - METHOD FOR PRODUCING A WASHING DISC ARRANGEMENT - Google Patents

Description

description

The invention relates to a method for producing an inclined or wobble plate arrangement in which a plurality of pistons are connected to a swash plate or swash plate so that an axial movement is caused by the swash movement of the swash plate is transferred to the piston, or vice versa. If the assembly is to be used in a fluid motor, propels the reciprocating movement of the pistons acts on the swash plate.

The invention provides a method with which ball-and-socket assemblies can be produced in a simple manner and with high accuracy (Ball joint assemblies) can be produced by telescoping sections of connecting rods together get connected. Ball joint assemblies are used extensively to provide combined axial, rotary and orbital motion to enable machines. Such machine parts include pistons, traction sheaves and crankshafts in pumps and compressors, Operating rods for presses and punching devices, Tie rods and other arrangements in conveyor systems. They are particularly suitable for use in swashplate arrangements, and this scope is described in the present invention.

Depending on the accuracy and / or strength required for the ball joint assembly, there are various methods of manufacturing the assembly. An example: A round, opening with a spherical bottom surface is inserted into the

030045/0625

'' Cup part incorporated by machining. This requires accurate and expensive tools. After the ball with its shaft is inserted into the opening, the wall of the opening must be made to enclose the ball to keep it in the pan as it moves. This can be done by rolling, Drop forging, pressing, rolling or some other deformation process can be achieved in which the wall of the opening is so deformed will that they the ball depending on the required strength of the connection and, depending on the required freedom of movement, encloses accordingly. Each of these common methods is a separate process in making the assembly, and the process is selected depending on economic considerations, the degree of accuracy or strength required the articulation and also to some extent depending on the materials used for the ball and the pan.

In order to produce fixed arrangements that are high and often resilient, and in order to produce precise arrangements with a precisely controlled play between ball and socket, a maximum degree of correspondence between ball and socket must be achieved. This maximum degree of conformity requires large deformations of the pan material, which in turn requires correspondingly time-consuming and costly methods and systems. A corresponding ^'r snug fit "also requires a large deformation of the socket material, which may necessitate the use of a soft, weak material and which favors cracking.

-5-

030045/0625

The high pressures required to deform the walls of the opening again require that the ball be made of a high strength material that will not damage when deformed will. This restricts the ball materials that can be used, and one with regard to the desired properties or economy has to compromise.

In addition to the problems outlined above, the high pressures in the shaping process do not necessarily allow full adaptation to the spherical surface of the sphere. Because of the incomplete shape and also because of "wrinkling" or bulging of the deformed materials, the forces applied will not be uniform over the spherical surface of the ball distributed. This results in local concentrations of the load, which in turn leads to overloading and damage. themselves can bring. Load concentrations also cause a great deal of wear and tear at the points of contact, which is the reason for the relative movement enlarged in the pan; this makes it difficult to pick up the load and also leads to premature failure.

All methods in which the balls are placed in the pan are such that precise dimensions of the arrangement cannot be sustained. In many applications, two or more ball and socket joints are connected to achieve the to produce the relevant machine part. The final dimensions of the device must be achieved by the fact that the complicated Arrangement is machined.

030045/0625

A two-part connecting rod is also disclosed in US Pat. No. 3,107,795 known where that part of the connecting rod which is connected to the piston, consists of a tube which telescopes over a shaft portion of the connecting rod bearing part engages. Otherwise, what has been said in connection with US Pat. No. 1,548,382 applies to this publication.

US Pat. No. 2,252,351 shows a casting process for producing a ball and socket joint between two parts.

U.S. Patent No. 3,763,535 shows a method of making a ball and socket joint between a connecting rod and a piston. The use of a certain one is particularly emphasized there Pressure for the molten material that is filled into the mold cavity during the die casting process.

The invention aims to provide an improved method of manufacturing a swash plate or swash plate arrangement. The invention is characterized in claim 1. Beneficial Refinements of the invention are given in the subclaims.

In a preferred method of making ball and socket joints the ball and its "accessories" are introduced during the manufacture of the pan by the fact that liquid, superplastic or powdered metal or polymer compounds are cast, preferably by die casting of molten Metal such as aluminum.

-8- 030045/0625

A spacer material is used in many mechanical forming operations or a coating is provided either on the ball or on the components to ensure that a certain relative movement is present between the ball and the socket, if only to ensure free movement. These "spacer materials" must be removed by dissolving, heating or mechanical means.

Other methods of making the ball joint assembly use wires, rods, or pins that allow escape Prevent the ball from getting out of the pan. This requires additional operations in order to attach the holding element to the socket body. Another method is to cut spherical recesses in two separate sections and then the join separate sections after enclosing the sphere. The connection can be made using fasteners / Springs, soldering, etc. are carried out.

To the state of the art in detail:

From US-PS 1 548 382 a piston and connecting rod construction is known in which the connecting rod consists of two Parts is made with a threaded connection between them, such that between the head of the piston and the center line of the bearing engaging the crankshaft can be adjusted. This patent does not show a casting process to connect the piston to the piston rod, nor to connect the connecting rod to the swash plate, and it shows not even a swashplate per se.

-7- 030045/0625

The pistons of pumps, compressors or fluid motors of variable displacement are driven by a traction sheave Connecting rods attached. The movements of both the pistons and the traction sheave require the flexibility of a ball joint connection. The arrangement can comprise a plurality of pistons which are fastened to the swash plate. The pistons can with regard to machined to their dimensions, their outer shape and annular grooves on the outer diameter and the top. On the other hand, the swash plate must be machined on the underside and on the inside diameter with regard to contour and flatness to be edited. The final length must be within a tolerance range of 0.025 mm to 0.050 mm (0.001 "- 0.002").

The invention is explained in more detail with the aid of the drawings. It shows:

Fig. 1 is a plan view

an oblique or Taume1sehe iben arrangement produced according to the invention;

Fig. 2 is a cross-sectional view taken along line 2-2 in Fig. 1; Fig. 3 is an exploded view of the piston unit and the

Swashplate unit before assembly; 4 shows a cross section through the piston unit.

Reference is first made to FIGS. 1 and 2. the Swash or swash plate arrangement is made from a swash plate or swash plate 10 and a plurality of pistons 12, wherein Connecting rods 14 extend between the piston 12 and the swash plate 10. Each connecting rod 14 consists of one

030045/0625 *

first section 16 with a spherical end 18 (FIG. 4) which is in a socket 20 formed on the underside of the piston sits. Extending from the end 18 of the connecting rod is a straight tubular section 22 telescoping on a second section 24 of the connecting rod. The section 24 has a spherical end 26 which is seated in a complementary socket 28, whereby a ball-socket connection between the section 24 of the connecting rod and the Swash plate 10 is formed.

The above describes the completed swashplate assembly. In the manufacture of swash plate manufacture, the following becomes preferred method used:

1. A steel ball forming the end 18 is connected to a tube forming the section 22. The tube is about 6.3 mm (1/4 ") longer than half the final length of the connecting rod, the thus formed ball-shaft assembly is coated with a mold-solvent and. 149 - 204 ⁰ C (300 - 400 ° F ) heated to drive off any volatiles in the coating, to preheat the ball, and to relieve the weld from stress.

2. The coated, preheated ball with shaft is placed in the cavity of a die casting machine as described in US Pat. No. 3,763,535 is described, used. The mold is closed and a casting is made using the conventional spin casting process.

-10-

030045/0625

3. After the solidified casting containing the ball and the shaft as an insert has been ejected, the piston is machined Machining brought to its final dimensions.

4. The swash plate 10 is produced in that the required Number of welded, coated and preheated ball-and-shaft units 24, 26 in the mold cavity are introduced and the casting is produced by this and then ejected. The swashplate casting with Inserts are brought to their final dimensions by machining.

5. The piston and swash plate units are placed in a holding device (not shown) used, which holds all parts in such a position that the connecting rods in their middle area to be connected; moreover, it sets the total length of the order to a value within the required Dimensions fixed before the connection process takes place.

6. The ball-and-socket connection in the center of the connecting rod is made by resistance welding, which results in the Arrangement is completed.

To illustrate this procedure (but without the procedure to the exemplary embodiments) are different embodiments of the manufacture of the swash plate arrangement described. For example, the material and manufacturing process of the balls may be of the same type as they are currently are available or used in practice, or

030045/0625 -n-

they can be specially selected / as may be required for a particular application. These special properties include strength, wear and corrosion resistance, or magnetic properties. For example, can hard or soft steel, cast iron, alloys based on * copper or aluminum or non-metallic materials, depending on required properties or economics considerations for which balls are used.

The ball can be attached to the relevant section of the connecting rod or an additional part by soldering, clamping, resistance or Fusion welding, adhesives or mechanical means such as screw threads can be attached. Also could be a one-piece Ball-shaft unit can be used as an insert in the casting process.

The section of the connecting rod or a corresponding additional part can be made of any material according to any Processes that ensure the desired properties and / or economy are produced. For example The telescopic arrangement can be made by cold heading, die forging, machining, casting or any other process used in molding materials. The connecting rods can Made of solid rod or pipe material or a combination of the two (one end solid, the other end tubular) getting produced. Regardless of the manufacturing process, the connecting ends should be in the middle of the connecting rod

-12- 030045/0625

be designed so that the connecting rod is easily assembled can be and allows an axial movement to produce the final dimensions.

The coating that is applied to the ball portion prior to pouring into the pan can be made of various materials exist and have a different thickness, as required for the desired properties or for reasons of economy is appropriate, or so that the coating with the lever position method or the selected Materials is compatible. For example, hardened steel balls, such as those used for ball bearings and those made by Resistance welding is associated with low carbon steel tubing material by being coated in an alcohol solution dipped or sprayed with finely divided graphite. If the ball is long enough at 204 ° C (400 ° F) is dried to evaporate all alcohol, to heat the entire ball-shaft assembly and the weld seam To make it stress-free, the ball is coated with a film or graphite. Similar suspensions in water, alcohol or other suspending agents can be used to create films of molybdenum bisulfite or other solid lubricants to deposit. The coating can be achieved by dipping or spraying polymeric materials made of polyethylene or polybutadienes that carbonize without coming into contact with the liquid metal or any other hot heat source Generate large amounts of steam in order to create a separating film between the ball and the pan, which allows free movement ensures.

030045/0625

The coating material prevents the ball and socket materials from sticking by creating a separating film between the both generated. The thickness of the release film can be determined by the mixture approach (Formulation) or controlled by repeated coating to a very specific, desired gap to manufacture. Ideally, the coating material also serves as a lubricant or as a material for initial grinding in the system, as is the case with graphite or carbonized polymer coatings. The choice of coating material depends on the variable of the arrangement including the materials, the casting process, the maintenance conditions, etc. from. Another example of such a choice can be a steel ball inserted into a pan made from an iron casting is to be coated with a sodium silicate (sodium silicate), which breaks open and as an abrasive for grinding in the Connection works. Furthermore, a steel ball, which is poured into a pan made of compact aluminum powder, can be used with a phosphate conversion coating to prevent separation and initial abrasion to achieve.

The extent to which the coated ball is preheated is determined by several factors of the coating and the process itself. For example, volatile binders and solvents in the coating must be driven off to avoid that large amounts of gas arise in the mold during the casting process. The extent to which the insert has been preheated is also chosen to give a certain deterrent and therefore an appropriate structure, solidity and strength as well

030045/0625 -14-

Co

3CR1323

receives a certain shrinkage of the liquid metal around the insert.

There are various methods available to those skilled in the art to insert the inserts during the pouring of the liquid or powdery Keep metals and polymers safe. To do this, adhesives, springs, Magnets, vacuums, etc. can be used. If required for construction, a core plug in the casting equipment can double The purpose is to hold the insert in place and also to provide an opening for lubricating the pan.

The casting method used to form the pan is selected based on considerations relating to the materials, special properties, or economy, as required for the type and number of parts to be manufactured. For example was the injection molding process that was used in connection with the exemplary embodiment for producing the pistons and drive plates was mentioned, selected on the basis of the quantities (economy) and the type of material that is used for the piston and the plate was required. The two parts could be made from the aluminum alloy # 380. It however, another aluminum-based alloy that is compatible with the injection molding process and provides the required may also be used has chemical and mechanical properties. Injection molding alloys can be based on magnesium and Zinc-based should be used if economic considerations or properties to be achieved permit or require this. Any other metal casting method can also be used based on the above considerations.

030045/0625 - ¹⁵ "

ORIQ) NAL INSPECTED

The shape of the socket is necessarily limited to encompassing the entire circumference of the sphere; it could also be partially be slotted such that greater movement is possible in one or more directions.

The manufacture of the pan in the context of the present invention is not limited to metals or the casting of liquids Metals. The ball inserts, as described, can be contained in pressed metal powder and to achieve the desired Properties are processed in a manner known per se. The pan can be made by potting polymeric materials be prepared by methods known per se.

The shape and function of the pan is not limited to the embodiment shown here as an exemplary embodiment; the pan rather, it can take any desired shape.

The assembly of the two or more cup assemblies which takes place at the end takes place in that the preformed sections connected to the connecting rod. For example, to assemble several pistons with a swash plate the finished pistons are inserted into a holding device, which also has the freely movable sections the connecting rods positioned. The swash plate is held in a similar holding device so that it can move freely Align connecting rod sections with the mating ends of the piston rods. The two assemblies are moved together to get the required final dimensions from the floor

-16-

030045/0625

the swash plate to affect the top of the piston. Leave the telescopic ends of the tie rod sections such lateral movement freely too. When the correct dimensions have been reached, the holding devices are attached, and the telescopic ends of the connecting rods become connected by a single resistance weld (spot weld) at each connection point. Either there will be several Welding heads or a rotary movement of the holding devices or a single welding head are used to complete all welds to manufacture.

030045/0625

Blank page

Claims (5)

Patent attorneys Dipl. Ing. H. Hauck Dipl. Phys. W. Schmitz Dipl. Ing. E. Graalfs Dipl. Ing. W. Wehnert Dipl. Phye. W. Carstens Dr.-Ing. W. Döring Mozartetraße 23 80OO Munich 2 Borg-Warner Corporation ■ · - · South Michigan Ave. Chicago, 111, 60604 Attorney's File M-5187 USA March 20, 1980 Method of making a swash plate assembly Claims; 1. A method for producing a swash plate or swash plate arrangement, characterized by the following steps: 1) making a plurality of piston units (12, 16, 18), each of which is made by (a) a first Section (16) of a connecting rod is made, at one end of which a substantially spherical Surface (18) is provided, and that (b) a piston (12) is die-cast so that part of the Piston accommodates the spherical surface (18) in a complementarily shaped socket (20) to form a ball-socket connection to manufacture; 2) Production of several second connecting rod sections (34), each one with a spherical surface (26) 030Q45 / 0625 ORIGINAL INSPECTED have provided end; 3) Casting a swash plate or swash plate (10) by die casting such that the ends of each second connecting rod section in a complementary socket (28) be added to ball-and-socket connections between the swash plate and the second connecting rod sections to build; 4) supporting the pistons at a fixed point with respect to the swash plate; 5) connecting the first and second tie rod sections . 2, method according to claim 1, characterized in that the Piston units are brought to their final dimensions by machining before they are connected to the swash plate. 3, method according to claim 1 or 2, characterized in that the swash plate is machined on Final dimension is brought before it is connected to the piston units. 4, method according to any one of the preceding claims, characterized characterized in that the first and second connecting rods Ab sehn it te be designed telescopically relative to each other. 030045/0625